Acute respiratory tract infections (ARIs) are the most common reason patients seek care in the United States and account for the majority of all antibiotic prescriptions. A large fraction of these prescriptions are inappropriate resulting in increased antibiotic resistance, unnecessary drug complications, and increased health care costs. Interventions to decrease ARI antibiotic prescribing have had limited success, highlighting the need to understand the factors that drive inappropriate prescribing. We believe that the reasons vary across settings and by type of provider. This is important because there is an ongoing shift in where patients receive care for ARIs from physicians to nurse practitioners and from outpatient practices to retail clinics. Retail clinics are clinics in drug stores and grocery stores that provide walk-in care for ARIs. Some have expressed concern that this shift in care will worsen inappropriate antibiotic prescribing for ARIs; others believe this shift will improve antibiotic prescribing. There has been limited prior research on this topic. In this exploratory study, there are two aims. In Aim 1, we will study whether this shift in care worsens or improves ARI antibiotic prescribing. Using national data sources we will measure antibiotic prescribing for ARIs by physicians and nurse practitioners at outpatient offices and retail clinics. In Aim 2, we will develop a survey that can be used to better understand the factors driving inappropriate antibiotic prescribing at different care sites. We will pilot test and validate an ARI provider survey that (a) uses clinical vignettes to judge the quality of antibiotic prescribing and (b) examines what factors drive the variation in antibiotic prescribing. We will validate the survey by comparing vignette- measured antibiotic prescribing quality to chart-measured antibiotic prescribing quality. Together the results of the two aims will provide the foundation for a larger study of a national sample of providers to see what factors drive variation in antibiotic prescribing. The results of the first aim may highlight important quality differences across providers and care sites. The second aim will support the development of a validated vignette survey, which can be used to examine factors that drive inappropriate antibiotic prescribing across care sites, geographic regions, and provider types. Our hope is that this future work will lead to targeted and tailored interventions to minimize inappropriate antibiotic prescribing. The study represents one of the first studies on a novel topic and might lead to important breakthroughs on an issue of clear public health importance, inappropriate antibiotic prescribing for ARIs. PUBLIC HEALTH RELEVANCE: Prior research has shown that antibiotics are prescribed too often for acute respiratory illnesses such as sinusitis or sore throat. More patients are now receiving care for acute respiratory illnesses from nurse practitioners at outpatient offices and retail clinics and some are worried that this will increase the number of patients who are inappropriately prescribed antibiotics. In this study we will see if this is the case. We will also develop a survey that can be used to study why providers inappropriately prescribe antibiotics. The work can be used in the future to tailor interventions to improve antibiotic prescribing.